System Security & Firewall Management Flashcards

Which firewalld zone is most appropriate for a highly trusted internal network interface?

Answer: trusted

The 'trusted' zone in firewalld accepts all connections and is designed for fully trusted networks.

What command permanently adds HTTP service to the active firewalld zone?

Answer: firewall-cmd --permanent --add-service=http

The --permanent flag ensures the rule persists across reboots; --reload is then needed to apply it.

Which SELinux command is used to change a file's security context permanently?

Answer: semanage fcontext

semanage fcontext adds a persistent policy rule, while chcon only changes the context temporarily.

What does the 'nmap -sS' scan type perform?

Answer: TCP SYN (stealth) scan

A SYN scan sends SYN packets and never completes the handshake, making it faster and less detectable than a full connect scan.

Which file configures system-wide PAM password quality requirements on RHEL-based systems?

Answer: /etc/security/pwquality.conf

pwquality.conf is read by the pam_pwquality module to enforce password complexity rules.

Which iptables target silently drops packets without sending any response?

Answer: DROP

DROP silently discards the packet, whereas REJECT sends an ICMP error back to the sender.

What is the purpose of the /etc/hosts.deny file in TCP Wrappers?

Answer: Denies access to specified hosts for wrapped services

TCP Wrappers checks /etc/hosts.allow first, then /etc/hosts.deny to determine whether to permit a connection.